Anyone ever carpeted their interior walls?

You guy may be hearing a lot from me in the next few months, After seeing new trailers NOT selling for 14 or 15 thousand and seeing the poor construction, I am building my own. Those new fangled trailers have a lot of stuff that you really do not need. thought crossed my mind of using a commercial grade indoor outdoor type carpet. Lots of things to consider, holding moisture is one, fire proofing would be another, I am still looking for a source of reasonably priced windows in the mid west. May take a 3 day weekend and head to Elkhart Indiana to see what they have. I am building a heavy floor/frame to have a strong foundation, I want to keep the shell very light. Any one ever used heavy fabrics, just to cover the interior and hide the wiring and insulation?? I am planning a plastic vapor barrier to keep moisture down. Has anyone ever used the tin framing joists?? Lets play 64 Questions!!!!! My build is going to be a standee, 14' long by 6'-3" wide. I hope to have the floor done this weekend, painted roofing tar on the underside of the sheets of plywood today. Once I get going on a project I do not know when to quit!!! Thanks [email protected] Bill